michael hollen Posted September 26, 2009 Report Share Posted September 26, 2009 88 starquest w/automatic trans starts and revs fine in nuetral, but as soon as you put it into gear it has rough idle and dies if you try to take off. Replaced fuel pump, injector clips, checked TPS (ok), checked timing (ok), new coil, wires and plugs. What else should I check, any help on this would be great! Link to comment Share on other sites More sharing options...
SQjunkie22r Posted September 26, 2009 Report Share Posted September 26, 2009 (edited) Can you give little more information does it run fine cold and as soon as it gets up to operating temperatures does it start doing it rough idle than dies than you start it up and it idles fines in park/neutral? If it does this its most likely your engine coolant sensor. Check the wires/sensor its self. Edited September 26, 2009 by SQjunkie22r Link to comment Share on other sites More sharing options...
newquest86 Posted September 26, 2009 Report Share Posted September 26, 2009 have you done a tps / isc reset ? also check for a vacum leak first Link to comment Share on other sites More sharing options...
michael hollen Posted September 26, 2009 Author Report Share Posted September 26, 2009 have you done a tps / isc reset ? also check for a vacum leak first I have not done the reset of the TPS/ISC, can you give me info on how to do this. Also the car idles fine cold or hot, just when you put it into drive and try to take off it will die, but if I have one foot on the gas and one foot on the brake I can feather the car to get up and down the street. Link to comment Share on other sites More sharing options...
mikec Posted September 26, 2009 Report Share Posted September 26, 2009 Go the FAQ and find the procedure for checking ECU error codes specific to your model year (one for early cars, one for 87-later models). I'll be the airflow sensor is not working correctly (AFS, also known as MAS) or ANY of the pipes from the lid of the air filter canister to the intake manifold have a leak. StarQuest intake systems MUST be sealed air-tight - no leaks - because the airflow sensor measures how much air is going to the engine and the ECU uses that to figure out how much gas to spray. If there are leaks, air gets into the engine AFTER the sensor (so the ECU doesn't "know" about it) and thus you get incorrect fuel quantity. A can of spray carb cleaner, dousing all hoses, connections, the intercooler, etc is an easy way to find leaks. If you spray and find ANYTHING that affects the idle (for better or worse) you've found a problem. Also, when you say you can't drive the car in gear:1: how hard/fast are you hitting the throttle? Can you baby it and get the car to drive up to 25 mph or so? If so, your "secondary" fuel injector (the one with green or blue plastic) is probably shot. If ANY load on the engine (tranny in gear) causes it to die, can't drive it at all, then I'd lean towards a busted airflow sensor or a massive vacuum leak. 2: On a stone-cold engine, what are your start-up RPMs? Leave the tranny in Park/Neutral. The RPMs should be around 1500 to 1600 for a half minute or so, then slowly crawling back down to 950 or so. If the cold-start idle RPM is NOT that high, then the ISC mechanism is either busted or not aligned/calibrated properly. The FAQ has a fairly simple procedure that aligns the ISC, TPS, etc. in an "idle adjustment" procedure. Find that test and follow it to the letter - no skipping steps. Also, if your throttle cable is too tight, the ISC can't do it's job. On a warmed-up engine, you should be able to push on the short exposed piece of throttle cable right next to the fuel injector area - and be able to push/deflect that exposed cable about 1/4 inch without affecting the RPMs. If not, the cable is too tight - not enough slack. Loosen the two nuts on the cable sheath that clamp to the support bracket... and walk the nuts so the sheath moves towards the injection mixer/throttle body assembly until you have the right slack. Next, with the engine idling (tranny in neutral or park), stand on the exhaust side of the engine and look at the injection mixer assembly... near the base of it, roughly below where the big air pipe connects, you'll see an angled screw that looks like an idle adjust screw. IT IS NOT AN IDLE ADJUSTMENT SCREW. That's the "fixed SAS" screw (you'll read about it in the FAQ idle procedure) and it's a "backup" to keep the ISC from going too stupid and totally shutting the throttle plates. Under normal operation, on a fully-warmed up idling engine, this screw should be 1 full turn OUT. Test your car: warm it up, let it idle... turn that screw clockwise until the RPMs just begin to increase. If you didn't get 1 full turn... your idle stuff is mis-adjusted and you really really need to do the FAQ idle procedure. Once you find where the idle RPMs increase (the "touch point") back off 1 full turn. See if your idle is better when you shift into gear now. If so, your ISC wasn't "working" before because the cable didn't have enough slack and/or the fixed SAS screw was screwed. StarQuests with auto trannies are supposed to "kick up" the throttle opening a little bit when the tranny is shifted from P or N into gear. The ISC does this; the ISC ("Idle Speed Controller") is a small electric motor run by the ECU to adjust the throttle plates. mike c. Link to comment Share on other sites More sharing options...
michael hollen Posted September 27, 2009 Author Report Share Posted September 27, 2009 Thankyou, I will try to check these area's when I get back to my fathers house ( dads car ) trying to get it running right again. Link to comment Share on other sites More sharing options...
michael hollen Posted October 6, 2009 Author Report Share Posted October 6, 2009 Hey guys, thanks for all the help. I gave my dad the MAS from my car and also EGR control solenoid valve that I had laying around and told him to install these pieces and to make sure all the hoses were tight (gave him something to do, he's retired!) He called me and said that he had drove the car around the block with no problems this time. Thanks http://www.starquestclub.com/forum/public/style_emoticons/default/rolleyes.gif Link to comment Share on other sites More sharing options...
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